No one understands the relationship between climate change and hummingbirds better than Audubon’s chief scientist Gary Langham. He led a groundbreaking study in 2014 that determined that about half of all North American bird species will lose their homes if we don’t do something to stop global warming. Now, to further that study, Audubon is sourcing data from people across the country who host hummingbirds in their backyards. The project, called Hummingbirds at Home, starts up again on April 8.

Langham emphasized the importance of Hummingbirds at Home to Audubon while answering questions about what will happen to the 18 or so hummingbird species in the United States (including rare visitors from Mexico) and the role citizen scientists play in ensuring their survival.

What were some of the regular challenges of a hummingbird migration even before climate change became a factor?

Gary Langham.Photo:Camilla Cerea/National Audubon Society

Well, any kind of migration, let alone a hummingbird, is sort of a minor miracle. Imagine a Ruby-throated Hummingbird crossing the Gulf of Mexico in one flight. How in the world does it have enough energy stored up in that little body? It’s just amazing. And then you factor in all of the threats it has to encounter, from weather to manmade structures.

So how has climate change made it worse?

If the nectar sources you depend on bloom too early, you run the risk of showing up after the party’s already over. That’s one of the things that got us thinking about Hummingbirds at Home. The Broad-tailed Hummingbird’s primary food source right now is this big yellow flower called the glacier lily. There’s research out of the University of Maryland showing that the bird is still arriving at its breeding grounds in the Rockies at the same time as previous years, but that climate change is causing the glacier lily to open up earlier and earlier in the season. It’s not hard to extrapolate that soon, Broad-tailed Hummingbirds may show up and not have their main food source. Maybe new flowers will take the glacier lily’s place. Or maybe this shift will turn out to be really bad for the bird.

Are some hummingbirds more endangered by climate change than others?

The hummingbird I grew up with in California, the Anna’s Hummingbird, was mercifully on the climate stable list (in the Audubon Birds and Climate Change Report). But unfortunately, one of the other coastal California hummingbirds, the Allen’s, is listed as climate-endangered. Its summer range seems to be decreasing, whereas the winter range is shifting northward pretty dramatically. The Rufous is also listed as climate-endangered. In some ways, it might be affected even more dramatically than the Allen’s. The other two species listed as climate-threatened are the Calliope and Black-chinned Hummingbirds.

So the Broad-tailed isn’t one of them?

While the Broad-tailed Hummingbird, in the way we did the climate report, was shown to be stable, its food sources are not. The food sources and a lot of ancillary things that are really important to animals are actually not included in our report. And that makes the prospects even more dire than what we projected.

How will Hummingbirds at Home help these species?

If we can better understand what the hummingbirds are feeding on, we can maybe get ahead of the curve and plant things that are either climate-stable or that will properly match up with the birds’ migrations. To me, the next iteration is to generate a specific list of plants that people can use for hummingbirds in their areas.

In the three years since Hummingbirds at Home started, what has stood out to you about the project?

People are very passionate about their backyards and gardens, and they’re very passionate about hummingbirds. Hummingbirds are like raptors. They somehow have this supernatural ability to capture people’s attention. Because hummingbirds come in people’s yards, they’re also a great way to engage kids. One of the things that’s kind of lost in our digital world is that connection to nature.

Is the eventual goal to have something as long-running and as scientifically useful as, say, the Breeding Bird Survey or the Christmas Bird Count?

I think that would be great! I hesitate to forecast anything for an individual project, but I could imagine that it would do just that. Or maybe we’ll broaden it to be more inclusive of a broader range of birds, or maybe it will be absorbed by something else. We want whatever it is we’re doing to feel meaningful to people and be fun and free and family-friendly.